Wet wells and liquid holding tanks often require pumping systems to ensure the water levels contained therein do not reach critically high or low levels. In most pumping systems, a pump is required to remove excess water from the wet well. Included in a pump is a volute, or an opening through which the velocity of a fluid is decreased as it is pumped out of the wet well. In most applications, the pump must remain submerged in liquid, as exposure to air will cause excessive vibration during the pumping operation, which may damage the pump. Similarly, exposing the pump to air may cause the pump to overheat.
To ensure the water level in the wet well does not become critically low, water level determination systems are typically used to control the pumping operation. Some water level determination systems use float sensors. These sensors include a float that may make contact with the water surface. The float may be moved from a hanging vertical position to a horizontal position as the float makes contact with the water, initiating the pumping operation.
Although floats are simple in their design, they can become subject to mechanical wear, corrode, or collect deposits from the liquid contained within the wet well, thereby affecting the accuracy of water level determination. Also, as the floats wear or corrode, particles may enter the liquid stored within the wet well or liquid holding tank. The release of these particles may contaminate certain fluids that require a high degree of purity. Furthermore, the presence of corrosion or deposits on the float mechanism may render the float inoperable, thus prohibiting the float from sensing the water level within the wet well.
In an attempt to overcome the deficiencies of floats, those in the art have created water level determination systems that operate by sensing the pressure of the liquid contained within the wet well. Typically, in pressure-based water level sensing systems, a pipe is extended into the wet well. The pipe may have an open end of the pipe submerged below the water level. The opposite end of the pipe typically includes a pressure transducer, which senses the pressure in the tank or wet well. The transducer operates by sensing the pressure level within the attached pipe, and relaying the data to a system that controls the operational state of the pumping system. Generally, the transducer relays sensory information to a switching mechanism, which may change the operational state of the pump when the pressure exceeds certain threshold values.
Despite the reliability improvements provided by the pressure based water level determination systems, the pipe that extends into the wet well may still collect deposits. Such deposits may lead to inaccurately sensing the water level within the wet well, thereby causing an undesired amount of water to be removed. To combat the collection of deposits, those in the art have implemented bubbler systems into the sensing pipes. Bubbler systems typically include an air pump, which injects air into the sensing pipe. Since one end of the sensing pipe is terminated at the transducer, the air is forced to bubble out of the submerged, open end. By bubbling air out of the pressure sensing pipe, the risk of forming deposits on the pipe may be significantly reduced.
Although the bubbler assists in reducing the likelihood of deposits on the open end of the sensing pipe, the bubbler causes vibrations that interfere with the accuracy of the transducer. There is no known structure or apparatus that can apply a bubbler structure to a sensing pipe, yet still maintain the high degree of accuracy achieved in the absence of a bubbler. This, a need exists for water level determination system to accurately determine the water level.